Glass electrode

摘要

This is used to measure the oxidation potential of liquid media. The sensor element (2) arranged in a hermetically tight manner on a tube (1) made of high-resistance glass no longer consists of a noble metal but of an electron-conductive glass. Situated in the interior of the electrode there is the current tap (3) which passes to the outside via the lead (5). The sensor element (2) consists of the following composition in parts by weight: SiO2 from 32 to 45; Me2O from 7.0 to 26.0, Me being at least two of the elements Li, Na and K; TiO2 from 16.0 to 40; Ti2O3 from 0.8 to 4.2; Nb2O5 and/or Ta2O5 from 2.0 to 32.0. By virtue of this design of the sensor element (2), chemical stability is considerably enhanced, so that the electrode can now be employed for measurements in strongly acidic media having a pH of less than 3, and temperatures of more than 60 DEG C in the presence of dissolved oxygen, hydrogen and catalytic poisons. <IMAGE>